Machine for processing powder or pastelike materials into a granulate or the like

ABSTRACT

A machine for processing or working powdery or pastelike materials into a granulate at the wedge gap between two opposite rotating rollers. A forming ring member rotates between the rollers, and the forming means are arranged at such ring member.

Umted States Patent 1 1 3,592,129

[72] Inventor Ileinz List [56] Relerences Cited s1. 1mm 43. Pratleln.Switzerland UNITED STATES PATENTS 2,093.40? 9/1937 Baker 1. 25/7024 '5?5" d $312,530 4/1967 Sackett 107/14 (P) l I 3,427,683 2/1969 Nazaruketal 18/12 (R) Primary Examiner- Edward L Roberts [54] MACHINE FORPROCESSING POWDER OR Ar1omey-Werner W. Kleeman PASTELIKE MATERIALS INTOA GRANULATE OR THE LIKE 4 Chllus. 5 Drawing Figs. U.S. 100/157,1811,25/76, IUD/I60. l00/l76, l07ll4 Int. Cl 830i: 3/04 Fkklrof Search[00/157,

I60. l76;'l8/l 5.12 R. IZA; 25/DIG.l3. 76; l07/8.3, 8.35. 8.55, H, l4.l.l4. 15.5, 54.65

ABSTRACT: A machine for processing or working powdery or pastelikematerials into a granulate at the wedge gap between two oppositerotating rollers. A forming ring member rotates between the rollers, andthe forming means are arranged at such ring member.

PATENTED JULI 3H? 3,592,129

SHEET 1 OF 2 MACHINE FOR PROCESSING POWDER OR PASTELIKE MATERIALS INTO AGRANULATE OR THE LIKE BACKGROUND OF THE INVENTION The present inventionrelates to an improved machine for the working or processing of powderyor pastelike materials into a granulate and, more specifically, is ofthe type wherein according to the invention the forming or molding meansor the forming apertures are not provided at the roller membersthemselves, rather at a forming ring which travels or revolves betweenboth of the roller members.

In the known prior art roller-granulation devices a pressure is exertedby the so-called wedge effect at the product between both of theoppositely rotating roller members. This pressure presses the productwhich is to be granulated through bores or into molds or forming meanswhich are arranged at one or both roller members. These prior artphysical constructions have the drawback that the grain size of thegranulate is limited at its lower dimension to about 3 millimeters.Likewise, it is often difficult to obtain a uniform length of thegranulate. If solid materials are processed, wherein the strength of thegranulate is determined by thermal techniques, for instance by coolingor chemical processes, then an operationally reliable processing of theproduct is difficult to attain. n the one hand, a marked differentiationbetween the plastic and the solid zone is not possible, and, on theother hand, an insufficient residence time exists between both zones.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of thepresent invention to provide an improved machine for processing powderyor pastelike material into a granulate which effectively overcomes theaforementioned drawbacks of the prior art structures.

Still a further important object of the present invention resides in theprovision of an improved machine for efiectively and reliably working orprocessing powdery or pastelike material into a granulate in aneconomical and highly efficient manner.

Now, in order to implement these and still further objects of theinvention, which will become more readily apparent as the descriptionproceeds, the inventive machine is generally manifested by the featuresthat the forming or moulding means or the forming apertures are arrangedin an intermediate ring member which is disposed between the rollermembers.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be betterunderstood, and objects other than those set forth above, will becomeapparent, when consideration is given to the following detaileddescription thereof. Such description makes reference to the annexeddrawings, wherein:

FIG. 1 is a cross-sectional view through a first embodiment of inventivemachine equipped with smooth roller members;

FIG. 2 is a longitudinal sectional view through the machine of FIG. 1,taken along the line A-B;

FIG. 3 is a cross-sectional view through a modified form of inventivemachine equipped with hollow roller means;

FIG. 4 is a longitudinal sectional view of the machine shown in FIG. 3,taken along the line C-D thereof; and

FIG. 5 is a cross-sectional view through a further form of inventivemachine equipped with two pairs of roller members, incorporating hollowroller means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, inFIGS. I and 2 there is schematically illustrated a first embodiment ofinventive machine equipped with a pair of smooth roller members I and 2A forming ring member 4 travels or rotates between the roller members Iand 2 at the wedge gap 3. This forming ring member 4 is either driven bythe friction prevailing in the wedge gap 3 or by means of teeth whichare provided at the roller member 1 which engage in lateral perforationsof the forming ring member 4. The material which is deposited in thewedge gap 3 is pressed by virtue of the wedge gap effect into theforming apertures or holes 5 provided at the forming ring member 4. Thisrevolving forming ring member 4 transports the thus formed molded orprocessed particles to the ejection device '7.

In the presently considered embodiment, this ejection device 7 comprisesa compressed-air pipe or conduit 7a. The pronounced air jets whichemanate through the nozzle means 8 eject or disburse the formedparticles 9 out of the forming apertures 5. This principle of ejectionof the material is generally employed for small granulate material inconjunction with appropriately suited apertured forming means. In thecase of larger formed particles mechanical ejection devices areemployed, the control of which takes place by means of the previouslymentioned lateral perforations of the forming ring member. If theforming ring member is very elastic, then, the ejection of the formedparticles can also occur by carrying out a pronounced deflection of theforming ring member by means of rollers or by a sudden jarring orjolting thereof. In order to prevent any premature dropping through ofthe powdery starting material in the wedge gap 3, the forming ringmember 4 can be guided past a guide or slide shoe 10. The latter isprovided with a trough II which simultaneously serves to collect anywaste material which is scraped away from the inner wall of the formingring member 4 by the edge I2 provided at this guide shoe 10.

The just described embodiment is particularly suitable for very smallgranulate, for instance having a diameter of l millimeter and a lengthof l millimeter, wherein the forming ring member is constructed topossess a thickness of only I millimeter. For larger briquetlike piecesthe forming means can also be arranged at only one side, that is to sayonly at the outside of the forming ring member.

If with the aforedescribed mode of operation it is desired to produceindividual formed particles or bodies in forming means which are closedat all sides, then in FIGS. 3 and 4 there is schematically illustratedan exemplary embodiment of a machine providing for continuous forming.For this case, a forming ring member 23 again rotates between the rollermembers 20 and 21. This forming ring member 23 is provided withnozzlelike constructed forming or molding apertures 24. The rollermember 21 is constructed to be smooth and provides a pressure roller,whereas the roller member 20 is pro' vided with a hollow compartment 25beneath the forming apertures 24 of the forming ring member 23, so thatthe strandlike product 27 which is pressed out of the wedge gap 26through the forming apertures 24 can freely escape. These strands ofmaterial or particles are cut into individual pieces 29 during furtherrotation of the forming ring 23 by means of the knife 28 and, in knownmanner, are transported away by means of a trough 22. For powderymaterials where the danger exists that it will fall through the formingapertures 24 at the region of the wedge gap 26, there is once againprovided the guide shoe 30.

FIG. 5 depicts a special embodiment of the invention in which there isundertaken a double forming of the material in order to improve itsconsolidation or compaction. In this instance. the forming ring member40 travels between two pairs of rollers 41, 42 and 43, 44, where in oneinstance the inner roller 41 and in the other instance the outer roller44 is constructed as a hollow roller, in other words provided with ahollow compartment in the manner previously explained during thediscussion of the embodiment of FIGS. 3 and 4. The material which isdeposited into the wedge gap 45, as described in connection with FIGS. 3and 4, is initially pressed inwardly. The thus-formed strands 46 or thelike are again engaged in the. other wedge gap 47 and pressed towardsthe outside, where they are cut into individual pieces by the knife 48,as shown. With an appropriate size of the forming ring member 40 it ispossible to also provide further pairs of rollers in the mannerpreviously considered.

The machine of the invention provides particular ad vantages during theprocessing or working of plastic materials which at the wedge gap, atelevated temperatures and in a molten plasticized condition, are pressedinto the forming ring member, and whereby the roller members are heated.By cooling the forming ring member during its further revolving path oftravel by means of blowing air or gas thereon, the formed particles ormaterial are cooled and solidified to such an extent that they can becut. The forming ring member after the cooling between the knife, alsowithout the wedge gap. can be again heated up by hot air or by inductivemeans.

Furthermore, in order to improve the wedge gap effect oftentimes oneroller member has imparted thereto a somewhat greater velocity andtherefore an improved friction is achieved at the wedge gap. A similareffect can also be achieved for different materials in that, one rollermember of the pair of rol lers is tangentially or radially oscillated atthe wedge gap, as such has been schematically depicted in FIG. 1 by theoscillating drive means 50.

The teachings of the invention can also be practiced with toothedrollers. In this case, then, the forming ring member is provided eitherexternally or internally with appropriate counter teeth, and whereby theforming apertures are then provided at the base of the teeth.

Thus, while there has been shown and described present preferredembodiments of the invention, it is to be distinctly understood that theinvention is not limited thereto but may be otherwise variously embodiedand practiced within the scope of the following claims. Accordingly,

I claim:

I. A machine for processing powdery or pastelike materials into agranulate comprising a pair of oppositely rotating roller means definingtherebetween a wedge gap at which the material is formed into agranulate, a ring member disposed to rotate between said pair of rollermeans, and forming means provided at said ring member, and wherein oneof said roller means is provided with a hollow compartment and saidrotat ing ring member bears against said one roller means, the other ofsaid roller means serving to press the material through the wedge gap sothat the product is pressed at one side by means of said other rollermeans into said ring member and at the opposite side of said ring memberis ejected into said hollow compartment of said one roller means.

2. A machine for processing powdery or pastelike materials into agranulate as defined in claim 1, wherein said forming means define aplurality of forming apertures.

3. A machine for processing powdery or pastelike materials into agranulate as defined in claim 1, wherein said ring member is fixedlylimited by said pair of roller means so that the length of the formedmaterial particles is determined by the thickness of said ring member.

4. A machine for processing powdery or pastelike materials into agranulate as defined in claim 1, wherein a number of pairs of rollermeans are arranged behind one another at said ring member, whereby thematerial is subjected to at least one additional processing step.

2. A machine for processing powdery or pastelike materials into agranulate as defined in claim 1, wherein said forming means define aplurality of forming apertures.
 3. A machine for processing powdery orpastelike materials into a granulate as defined in claim 1, wherein saidring member is fixedly limited by said pair of roller means so that thelength of the formed material particles is determined by the thicknessof said ring member.
 4. A machine for processing powdery or pastelikematerials into a granulate as defined in claim 1, wherein a number ofpairs of roller means are arranged behind one another at said ringmember, whereby the material is subjected to at least one additionalprocessing step.